Replace BouncyCastle's deprecated AESFastEngine with the default AESEngine

- Update AESEngine to use the default AES engine, following BouncyCastle's recommendations
  (see release-1-56 of changelog: https://www.bouncycastle.org/download/bouncy-castle-java/?filter=java%3Drelease-1-56).
- Migrate to the latest API 'newInstance()' method to allow removal of @SuppressWarnings("deprecation")
- Remove @SuppressWarnings("deprecation")

crypto/src/main/java/org/springframework/security/crypto/encrypt/BouncyCastleAesCbcBytesEncryptor.java

@@ -18,6 +18,7 @@ package org.springframework.security.crypto.encrypt;
 
 import org.bouncycastle.crypto.BufferedBlockCipher;
 import org.bouncycastle.crypto.InvalidCipherTextException;
+import org.bouncycastle.crypto.engines.AESEngine;
 import org.bouncycastle.crypto.modes.CBCBlockCipher;
 import org.bouncycastle.crypto.paddings.PKCS7Padding;
 import org.bouncycastle.crypto.paddings.PaddedBufferedBlockCipher;
@@ -45,23 +46,21 @@ public class BouncyCastleAesCbcBytesEncryptor extends BouncyCastleAesBytesEncryp
 	}
 
 	@Override
-	@SuppressWarnings("deprecation")
 	public byte[] encrypt(byte[] bytes) {
 		byte[] iv = this.ivGenerator.generateKey();
 		PaddedBufferedBlockCipher blockCipher = new PaddedBufferedBlockCipher(
-				new CBCBlockCipher(new org.bouncycastle.crypto.engines.AESFastEngine()), new PKCS7Padding());
+				CBCBlockCipher.newInstance(AESEngine.newInstance()), new PKCS7Padding());
 		blockCipher.init(true, new ParametersWithIV(this.secretKey, iv));
 		byte[] encrypted = process(blockCipher, bytes);
 		return (iv != null) ? EncodingUtils.concatenate(iv, encrypted) : encrypted;
 	}
 
 	@Override
-	@SuppressWarnings("deprecation")
 	public byte[] decrypt(byte[] encryptedBytes) {
 		byte[] iv = EncodingUtils.subArray(encryptedBytes, 0, this.ivGenerator.getKeyLength());
 		encryptedBytes = EncodingUtils.subArray(encryptedBytes, this.ivGenerator.getKeyLength(), encryptedBytes.length);
 		PaddedBufferedBlockCipher blockCipher = new PaddedBufferedBlockCipher(
-				new CBCBlockCipher(new org.bouncycastle.crypto.engines.AESFastEngine()), new PKCS7Padding());
+				CBCBlockCipher.newInstance(AESEngine.newInstance()), new PKCS7Padding());
 		blockCipher.init(false, new ParametersWithIV(this.secretKey, iv));
 		return process(blockCipher, encryptedBytes);
 	}

crypto/src/main/java/org/springframework/security/crypto/encrypt/BouncyCastleAesGcmBytesEncryptor.java

@@ -17,6 +17,7 @@
 package org.springframework.security.crypto.encrypt;
 
 import org.bouncycastle.crypto.InvalidCipherTextException;
+import org.bouncycastle.crypto.engines.AESEngine;
 import org.bouncycastle.crypto.modes.AEADBlockCipher;
 import org.bouncycastle.crypto.modes.GCMBlockCipher;
 import org.bouncycastle.crypto.params.AEADParameters;
@@ -44,21 +45,19 @@ public class BouncyCastleAesGcmBytesEncryptor extends BouncyCastleAesBytesEncryp
 	}
 
 	@Override
-	@SuppressWarnings("deprecation")
 	public byte[] encrypt(byte[] bytes) {
 		byte[] iv = this.ivGenerator.generateKey();
-		GCMBlockCipher blockCipher = new GCMBlockCipher(new org.bouncycastle.crypto.engines.AESFastEngine());
+		GCMBlockCipher blockCipher = (GCMBlockCipher) GCMBlockCipher.newInstance(AESEngine.newInstance());
 		blockCipher.init(true, new AEADParameters(this.secretKey, 128, iv, null));
 		byte[] encrypted = process(blockCipher, bytes);
 		return (iv != null) ? EncodingUtils.concatenate(iv, encrypted) : encrypted;
 	}
 
 	@Override
-	@SuppressWarnings("deprecation")
 	public byte[] decrypt(byte[] encryptedBytes) {
 		byte[] iv = EncodingUtils.subArray(encryptedBytes, 0, this.ivGenerator.getKeyLength());
 		encryptedBytes = EncodingUtils.subArray(encryptedBytes, this.ivGenerator.getKeyLength(), encryptedBytes.length);
-		GCMBlockCipher blockCipher = new GCMBlockCipher(new org.bouncycastle.crypto.engines.AESFastEngine());
+		GCMBlockCipher blockCipher = (GCMBlockCipher) GCMBlockCipher.newInstance(AESEngine.newInstance());
 		blockCipher.init(false, new AEADParameters(this.secretKey, 128, iv, null));
 		return process(blockCipher, encryptedBytes);
 	}